German Patent No. 41 10 800 describes a module for insertion into HF-proof housings of electronic equipment. The module has a front plate constructed in a "U" shape profile. A spring strip including a plurality of spring elements following one another in a chain-like manner is provided for the purpose of high-frequency sealing of the longitudinal gaps between the front plates of modules arranged parallel to one another, for example in a subrack. The spring strip is plugged onto the longitudinal web forming one side of the U-shaped profile of the front plate of a module, and makes contact electro-magnetically and in a radio-frequency-proof fashion between the front plate and the opposite longitudinal strip forming the other side of the U-shaped profile of the front plate of a neighboring module.
A spring element of the spring strip includes two identically constructed contact springs each having a spring leaf and, arranged between a spring clamp and a clamping leaf. The contact springs and the spring clamp have a common, flat rear leaf. The spring clamp and rear leaf are constructed with a U-shaped cross-section and can be plugged onto the longitudinal web of the front plate in a clamping fashion such that the rear leaf rests on the inside of the longitudinal web. The contact springs and rear leaf have a V-shaped cross-section, with the result that their spring leaves are spread away by the outside of the longitudinal web.
One problem in this arrangement is that a proper and sufficient clamping action requires that the cooperating elements of spring clamp and rear leaf and the longitudinal web onto which these elements are plugged are of sufficient height. The essential cause of the latter is that the retaining action is achieved overwhelmingly through the use of friction forces. A further problem is that the element of the spring clamp must furthermore be of sufficient width on the front of the spring element to achieve the required clamping action. The effect of this is that the spacing between the contact springs arranged on both sides of the spring clamp is relatively large. To achieve continuous contact and thus a sufficient screening action, it is necessary for the spring leaves to be connected to one another by a connecting bridge in the lower region. Since, however, the high spring clamp situated between the connecting bridge can be constructed only to be narrow and like a web, the risk of mechanical damage to it is high.